I found solution for merlin cam feeds oe2 on dm800
you have to edit name of plugin and add -nf before .ipk
Tested working by me now cams showing in add ons
root@dm800:~# cd /
root@dm800:/# opkg install /tmp/merlin2-cam-feed_1.0-r2_mips32el-nf.ipk
Installing merlin2-cam-feed (1.0-r2) to root...
Configuring merlin2-cam-feed.
root@dm800:/#
install tspanel for oe2.0 and download merlin cams from addons or through tspanel emumanager(tspanel cams same as merlin)